Replies

1. 
   JohnCA07 | May 27, 2010 01:42pm | #1

   Maybe an image will help

   Here are my current options as I know them.

   Is one proposed option better then another?

   Do you know of a better way to install girders in this situation?

   Thanks.

    

   
1. 
   davidmeiland | May 27, 2010 02:44pm | #2

   If you don't have beam pockets

   in the wall, then you need a hanger or a post. I have not seen hangers attached to concrete directly, but you might talk to Simpson's tech people and see what they say. A post under each end of the girder would work fine, you would probably use a metal column cap and skip the ledger. Bolting the ledger to the wall and hanging the girder seems a little odd to me, because you don't really need a ledger, you just need a block of wood to carry the hanger. I would go with the post detail and skip the ledger in the drawing.

1. 
   JohnCA07 | May 27, 2010 05:38pm | #4

   No pockets in the wall unfortunately. 

   I did check with Simpson and they have to direct concrete hanger options. Parts LGUM46 or HU46. Of the two, the only one I could use here is the HU46 since it only requires a 1.5" drop from the top of the stem wall the other requires a 4" drop.

   The pressure treated post option does seem to be a solid solution but would put wood near the dirt and this area has lots of termites.

   Thanks for the input and suggestions.

1. 
   DanH | May 27, 2010 08:13pm | #6

   Pour a concrete post.

2. 
   harryv | May 27, 2010 04:35pm | #3

   subfloor ledger to concrete

   If I had my druthers, I'd use option A. Hard to go wrong posting down to concrete. Might use a few Simpson titan screws to fasten the PT ledger to the foundation.

1. 
   JohnCA07 | May 27, 2010 05:53pm | #5

   That's two votes for the post support option.

   If not behind the girders, I'll still need to attach ledgers to the concrete and I like the idea of using the Simpson Titen HD concrete connectors.

   Do you have any input on speed or ease of install comparing concrete wedge anchors with the Titen HD screw anchors?

   Thanks for the suggestions.

2. 
   JohnCA07 | Jun 10, 2010 01:55pm | #7

   next step question

   Progress / status so far:

   Okay so the floor is being installed using concrete piers and PT posts.  At the ends of each girder, they are attached to the 8" think concrete wall using Simpson HUC46 Zmax hangers and 12 Simpson 1 3/4" titan screws. The concrete piers are very close to the perimeter foundation wall so the Simpson hangers seem very underutilized at this point.

   My next step is to install pressure treated ledgers to the concrete wall between each Simpson hanger. The girders/hangers are set 36" apart. It was suggested to upgrade from 2x6 to 3X6 pressure treated to avoid splitting the ledger when nailing or screwing down the 1-1/8" T&G subfloor.

   Question:

   My question is, how much support do these ledgers require for such short spans (36"). I was considering using the Simpson titan HD concrete screws with a large washer.  The thing is, the ledgers are only 6' tall so placing the screws in a standard top and bottom pattern would place them pretty close together on a 3x6 ledger board.  Ideas and suggestions for attaching these ledgers would be appreciated.

   Thanks

   
1. 
   davidmeiland | Jun 10, 2010 07:20pm | #8

   I would use

   two concrete anchors per ledger section, about 6" from each end and about 2" from the bottom of the ledger O.C.

   But, I'm unclear on your detail here. You say there's going to be 1-1/8" subfloor on top of the framing. In the drawing it appears that the subfloor is going to sit right on top of the concrete wall. This is not common. What is going to stop the plywood from absorbing moisture from the concrete and eventually rotting?

   It's very likely that you should have a mudsill in this detail, and that you could have hung the girders from the mudsill using a top-flange hanger, such as the BA, and omitted the ledger pieces altogether.

   Or is there something I'm not seeing here? Are you proceeding upward with more concrete?